Method of controlling flow of cooking medium using multiport/rotary valve sensor using hall effect control

ABSTRACT

Systems and methods for delivering a cooking medium in a cooking apparatus are disclosed. A delivery system includes a rotary valve having a rotary inlet and a plurality of rotary outlets. The rotary inlet is configured to be in fluid communication with a source of cooking medium and the plurality of rotary outlets are configured to be in fluid communication with a corresponding plurality of receptacles. A rotary position sensor generates a signal, having continuous angular position resolution, based on an angular position of the rotary valve. A controller receives the signal generated by the rotary position sensor and selectively places the rotary inlet in fluid communication with one of the plurality of rotary outlets based on the signal generated by the rotary position sensor. The rotary position sensor may include a Hall-effect sensor that functions at elevated operating temperatures associated with the cooking medium.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of and claims the priorityof U.S. application Ser. No. 15/458,346, filed Mar. 14, 2017, whichclaimed the priority of Provisional Application Ser. No. 62/309,650,filed Mar. 17, 2016, the disclosures of which are incorporated byreference herein. This disclosure is also related to U.S. Pat. No.9,528,510, the disclosure of which is incorporated by reference herein.

TECHNICAL FIELD

The invention generally relates to fryers used for cooking foodproducts, and in particular, to systems and methods for managingrecirculation of a cooking medium of a fryer system.

BACKGROUND

Oil-based frying is commonly used as a cooking method for a wide rangeof food products, such as poultry, fish, potato products, and the like.Commercial fryers include one or more fry pots that are filled with acooking medium such as oil or solid fats. Heat is typically provided tothe cooking medium using an electrical heating element submerged in thecooking medium or a gas burner thermally coupled to the cooking mediumthough the walls of the fry pot. When the cooking medium reaches apreset cooking temperature, food products are placed into the cookingmedium for a predetermined amount of time during which the food productsare cooked by heat from the cooking medium. To facilitate insertion andremoval of the food products, the food products are typically placedinside a container, such as a wire basket, and the container is loweredinto the cooking medium for the predetermined amount of time.

The cooking medium is normally re-used for multiple cooking cycles,which may include cooking cycles for different food products. However,the cooking medium degrades over time. This degradation may be due tocontamination by particles shed by the food products being cooked andfrom chemical degradation due to heat, oxidation, and reactions with thefood products. In addition, as food particles accumulate in the cookingmedium, the flavor characteristics of the food particles may becomeinfused in the cooking medium. This infusion may adversely affect thequality of cooked food. For at least these reasons, the cooking mediummust occasionally be replaced.

To maintain cooking quality and to prolong the operational lifetime ofthe cooking medium, the cooking medium may be filtered periodically. Thefiltering process removes cooking by-products, such as suspended foodparticles ranging from dust-sized particles to larger pieces ofcrackling and small pieces of food product. Frequent filtering mayextend the useful life of the cooking medium, thereby reducing the costof operating the fryer by reducing the frequency with which the cookingmedium must be replaced. The cost savings from filtering may beparticularly beneficial when using a cooking medium that containsreduced amounts of trans fats, which have become popular, but aretypically more expensive than other types of cooking media. Thus, it maybe economically beneficial to frequently filter the cooking medium toextend its useful life.

Some conventional pressure and open fryers include automated oilmanagement systems which route oil through fryer subsystems toaccomplish oil management tasks such as recirculation, filtering, anddiscarding used oil. To avoid mixing multiple types of cooking media ina vessel, some conventional fryer systems use a system of plumbing, suchas pumps, check valves, and solenoid valves to regulate the return ofthe cooking medium to the fryer from which the cooking medium wasfiltered. In some conventional fryers, each cooking vessel may have itsown corresponding pumps, check valves, and solenoid valves.

In some systems, as many as eight fry pots or divided cooking chambersare included in each fryer. These additional parts cause the fryer totake up a larger space than would otherwise be necessary. Further, theadditional piping and cooking medium routing elements require morecooking medium than otherwise would be necessary for a fryer systemusing some shared components. In the interest of increasing throughputby providing a greater number of fry pots while maintaining efficientuse of space, there is a need to reduce the amount of space required tohouse the components of the fryer. To this end, it is desirable toenable a plumbing system to operate with multiple different fry ports orcooking chambers.

A previous version of a solution to address some of these problems isshown at U.S. Pat. No. 9,528,510, which is owned by the originalassignee of this disclosure. That patent provides a multiport rotaryvalve for directing flow between one or more cooking medium sources andone or more cooking chambers. The position control for the valve isperformed mechanically with cams and switches in this version. Themechanical cams and switches are subject to wear out and/or be affectedin operation when oil vapor or water is present, which may occur in theenvironment fryers are located. To this end, the generally harshenvironmental conditions (temperature and oils/dusts in the air) aroundfryers can make it difficult to assure reliability of sensors andcontrol systems for such valves. If the position sensing of the rotaryvalve becomes inaccurate, cooking medium being filtered through afiltration system could potentially be routed back to the wrong cookingchamber, and as such, it would be desirable to develop a system thatavoids such possibilities.

SUMMARY

The disclosed embodiments overcome the above-described shortcomings ofthe related art and provide systems, methods, and computer programproducts that provide increased throughput and efficient use of space. Atechnical advantage of the disclosed systems is that multiple solenoidvalves may be replaced by a single rotary valve and may reduce the sizeand complexity of the fryer, improve performance, and/or reduce cost ofautomatic filtration systems. Further, the disclosed embodimentsovercome problems that may arise in components related to motion of therotary valve through the use of a rotary position sensor that isconfigured to sense an angular position of the rotary valve withoutmaking mechanical contact with the rotary valve.

A cooking apparatus including at least one cooking medium source, one ormore cooking vessels, a cooking medium receptacle, and a plumbingsystem, is disclosed. The cooking medium receptacle is configured toreceive and store used cooking media to be discarded, and the plumbingsystem is configured to transport the cooking medium between the cookingmedium source, the one or more cooking vessels, and the cooking mediumreceptacle. The cooking apparatus further includes a rotary valvecontrolling flow through the plumbing system and having at least onerotary inlet and a plurality of rotary outlets. The at least one rotaryinlet is configured to be in fluid communication with the at least onecooking medium source, one or more of the plurality of rotary outletsare configured to be in fluid communication with the corresponding oneor more cooking vessels, and a rotary outlet is configured to be influid communication with the cooking medium receptacle.

The cooking apparatus further includes a rotary position sensor and acontroller. The rotary position sensor generates a signal, havingcontinuous angular position resolution, based on an angular position ofthe rotary valve. The controller receives the signal generated by therotary position sensor and selectively places the rotary inlet in fluidcommunication with one of the plurality of rotary outlets based on thesignal generated by the rotary position sensor. The rotary positionsensor may further include a Hall-Effect sensor that provides accuratereadings of the angular position of the rotary valve while operating inenvironments at temperatures up to 400° F.

The cooking apparatus may further include a temperature sensor mountedin the rotary valve that determines a temperature of the cooking mediumthat flows through the rotary valve. The cooking apparatus may furtherinclude one or more temperature sensors that measure temperature of thecooking medium at one or more corresponding first locations within theplumbing system, and one or more heating elements located within theplumbing system that provide heat to the cooking medium at one or morecorresponding second locations within the plumbing system. Thecontroller receives signals from one or more temperature sensors andprovides signals to the one or more heating elements to controltemperature within the plumbing system based on the signals receivedfrom the one or more temperature sensors according to a predeterminedtemperature profile.

The cooking apparatus may further include a filtration system that is influid communication with the one or more cooking vessels. The filtrationsystem is configured to receive and filter used cooking media from theone or more cooking vessels and to provide the filtered cooking media tothe rotary inlet as the cooking medium source. The controller is furtherconfigured to control movement of the cooking medium through theplumbing system and to control the filtration system to perform afiltration operation.

A method of transferring a cooking medium to various parts of a cookingapparatus is disclosed. The method includes detecting an angularposition of a rotary valve, rotating the rotary valve to selectivelyposition a rotary inlet of the rotary valve in fluid communication withone of a plurality of rotary outlets based on the detected angularposition, and transferring the cooking medium from a cooking mediumsource that is in fluid communication with the rotary inlet to adestination receptacle that is fluid communication with one of theplurality of rotary outlets.

The method further includes detecting an angular position of the rotaryvalve using a rotary position sensor that generates a signal, havingcontinuous angular position resolution, based on the angular position ofthe rotary valve and that senses angular position of the rotary valvewithout making mechanical contact with the rotary valve. The method mayfurther include detecting an angular position of the rotary valve usinga Hall-Effect sensor that provides accurate readings of the angularposition of the rotary valve while operating in environments attemperatures up to 400° F.

The method may further include controlling a temperature within aplumbing system of the cooking apparatus according to a predeterminedtemperature profile. The method includes measuring a temperature of thecooking medium at one or more first locations within the plumbing systemof the cooking apparatus, and proving heat to one or more secondlocations within the plumbing system of the cooking apparatus based onthe measured temperatures at the first plurality of locations.

The above summary may present a simplified overview of some embodimentsof the invention in order to provide a basic understanding of certainaspects of the invention discussed herein. The summary is not intendedto provide an extensive overview of the invention, nor is it intended toidentify any key or critical elements, or delineate the scope of theinvention. The sole purpose of the summary is merely to present someconcepts in a simplified form as an introduction to the detaileddescription presented below.

Further embodiments, features, and advantages, as well as the structureand operation of the various embodiments, are described in detail belowwith reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate various embodiments of theinvention and, together with the general description of the inventiongiven above, and the detailed description of the embodiments givenbelow, serve to explain the embodiments of the invention. In thedrawings, like reference numbers generally indicate identical,functionally similar, and/or structurally similar elements.

FIG. 1 is a top perspective view of a fryer according to an embodimentof the invention.

FIG. 2 is a diagrammatic view of the fryer of FIG. 1 depicting aplurality of fry pots, a filtration system, and a controller.

FIG. 3 is a diagrammatic view of the controller of FIG. 2.

FIG. 4A is a perspective view of a rotary valve, according to anembodiment.

FIG. 4B is a side view of the rotary valve of FIG. 4A.

FIG. 5 illustrates a set of positions of an inner cylinder within arotary valve, such as the valve shown in FIGS. 4A and 4B.

FIG. 6 is a schematic illustration of the operation of a Hall-effectdevice for sensing magnetic fields, according to an embodiment.

FIG. 7A is a schematic illustration of a configuration in which aHall-effect sensor is used to determine an angular position of amagnetic field source, which may be used with the valve shown in FIGS.4A and 4B.

FIG. 7B is a schematic illustration of a Hall-effect voltage vs. angularposition of a magnetic field source, in accordance with the exampleshown in FIG. 7A.

FIG. 8A is a schematic illustration of a configuration in which threeHall-effect sensors are used to determine an angular position of amagnetic field source, according to another embodiment that may be usedwith the valve shown in FIGS. 4A and 4B.

FIG. 8B is a schematic illustration of Hall-effect voltages vs. angularposition generated by the three sensors of FIG. 8A.

FIG. 9 is a flowchart illustrating a method of operating a cookingapparatus, including transferring a cooking medium to various parts ofthe cooking apparatus.

DETAILED DESCRIPTION

Embodiments of the invention are directed to systems and methods ofcontrolling a fryer, and in particular, such that a recirculationprocess performed by a cooking medium handling system is capable ofserving multiple fry pots and/or cooking chambers with the sameequipment. In order to improve the accuracy and reliability of suchsystems, Hall-effect sensors and temperature sensors are used with thecontrol of elements such as valves to assure that the cooking medium isrouted to and from the flow paths in the plumbing that are desired.Therefore, problems with incorrect valve and/or recirculation systemoperation can be avoided.

Referring now to the figures, FIG. 1 depicts an exemplary fryer 10 (acooking apparatus) in accordance with an embodiment of the invention.The fryer 10 includes fry pots 12, 14, a cabinet 16, control panels 18,20, access panels 22, 24, wheels 26, a basket hanger 28, and abacksplash 30. Each of the fry pots 12, 14, cabinet 16, access panels22, 24, basket hanger 28, and backsplash 30 may be constructed fromstainless steel, mild steel, or some other suitable material. Each frypot 12, 14 includes a respective opening 13, 15 though which a foodproduct may be placed into the fryer 10.

Food products may be placed into the fry pots 12, 14, for example, bylowering a basket containing the food product into the fry pot 12, 14.At completion of a cooking cycle, the basket may be removed from the frypot 12, 14 and hung from the basket hanger 28 to allow excess cookingmedium to drain back into the fry pot 12, 14. Each of the fry pots 12,14 may be associated with a corresponding one of the control panels 18,20 to provide a human-machine interface for operating the fryer 10. Thecontrol panels 18, 20 may receive commands from, and display informationregarding a status of the fryer 10 to an operator. The access panels 22,24 may provide access to the interior of cabinet 16 to, for example,service internal components of the fryer 10.

Exemplary fryer 10 is depicted as having a separate control panel 18, 20for each fry pot. However, it should be understood that one controlpanel could be configured to control multiple fry pots, and embodimentsof the invention are not limited to fryers having a separate controlpanel for each fry pot. In addition, although the fryer 10 depicted inFIG. 1 is a gas-heated open fryer having two fry pots, it should befurther understood that embodiments of the invention may also be usedwith pressure fryers and/or electrically heated fryers, as well asfryers having a different number of fry pots.

FIG. 2 is a diagrammatic view of the fryer of FIG. 1 depicting aplurality of fry pots, a filtration system, and a controller, accordingto an embodiment. In addition to fry pots 12, 14, the fryer 10 mayinclude a cooking medium handling system 100 and a controller 200. Eachfry pot 12, 14 may include a heating element 32 (schematically shown), atemperature sensor 34, a fill port 36, and a drain port 38, and may beat least partially filled with a cooking medium 40. Suitable cookingmediums may include plant-based fats, animal-based fats, and/orsynthetic (e.g., hydrogenated) fats. The heating element 32 may bedisposed within or proximate to the fry pot 12, 14 for heating thecooking medium 40. The heating element 32 may include an electricalheating element (e.g., a heating coil immersed in the cooking medium 40)or a gas heating element (e.g., a gas burner and heat exchanger thattransfers heat from the burner to the cooking medium 40).

The cooking medium handling system 100 may include drain valves 102,104, a drain manifold 106, a drain pan 108, a filter assembly 110, afilter pump 112, a reservoir 114 of fresh cooking medium, a reservoirpump 116, and a selector valve 118. The selector valve 118 may include aplurality of inlet ports 120-122 and a plurality of output ports124-127. A temperature sensor 128 may be located in the selector valve118, or in another suitable location, to enable the controller 200 todetermine the temperature of the cooking medium passing through thecooking medium handling system 100.

The selector valve 118 is configured to selectively fluidically coupleone or more of the inlet ports 120-122 to one or more of the outputports 124-127. To this end, the selector valve 118 may comprise a rotaryvalve having a transverse plug (not shown) coupled to a motor 130. Themotor 130 may cause the selector valve 118 to fluidically couple aselected inlet port to a selected output port by rotating the transverseplug to one of a plurality of predetermined positions. In an alternativeembodiment of the invention, the selector valve 118 may comprise anassembly of valves that are configured to provide the desired selectivefluidic coupling in response to signals from the controller 200. In thisalternative embodiment, the selector valve 118 may comprise an assemblyincluding a plurality of valves connected to a manifold.

The filter pump 112 and reservoir pump 116 may each include an inlet132, 134 on a suction side of the pump, and an outlet 136, 138 on apressure side of the pump. The inlet 132 of filter pump 112 may befluidically coupled to the drain pan by the filter assembly 110, and theoutlet 136 of the filter pump 112 may be fluidically coupled to an inletport 120 of selector valve 118. Activation of the filter pump 112 maycause cooking medium 40 to be drawn from the drain pan 108 through thefilter assembly 110 and provided to selector valve 118. The selectorvalve 118 may in turn provide the filtered cooking medium 40 to one ofthe fry pots 12, 14 for reuse and/or to a discard port 140 for disposal.

Although filter assembly 110 is depicted as being coupled to the inlet132 of filter pump 112 in the exemplary embodiment illustrated by FIG.2, it should be understood that the cooking medium handling system 100is not limited to the specific arrangement of components depicted. Forexample, the filter assembly 110 could be coupled to the outlet 136 offilter pump 112 rather than the inlet 132 so that cooking medium 40 ispushed through the filter assembly 110 rather than drawn through thefilter assembly 110. In either case, the filter assembly 110 may includea housing configured to accept a filter for filtering the cooking medium40. Regular use of filtration cycles to clean the cooking medium 40 mayreduce consumption of cooking medium 40 and increase the availability ofthe fryer 10 by providing hot filtered cooking medium 40 to the fry pots12, 14.

The inlet 134 of reservoir pump 116 may be fluidically coupled to thereservoir 114, and the outlet 138 of the reservoir pump 116 may befluidically coupled to an inlet port 121 of selector valve 118.Activation of reservoir pump 116 may cause cooking medium 40 to be drawnfrom reservoir 114 and provided to selector valve 118. The selectorvalve 118 may in turn provide the fresh cooking medium 40 to one of thefry pots 12, 14 to refill or replenish the cooking medium 40. A fillport 142 may be coupled to an inlet port of the selector valve 118 tofacilitate the addition of cooking medium 40 to the reservoir 114. Thecooking medium handling system 100 may further include check valves143-147 that prevent cooking medium 40 from back-flowing from the frypots 12, 14 into the selector valve 118, or from the selector valve 118into any of the filter pump 112, reservoir pump 116, or fill port 142.

The controller 200 may be in communication with the heating element 32and temperature sensor 34 of each of the fry pots 12, 14, the drainvalves 102, 104, filter pump 112, reservoir pump 116, and temperaturesensor 128 and motor 130 of selector valve 118. The controller 200 maycontrol the various cooking and maintenance cycles of the fryer 10 bytransmitting signals to, and receiving signals from these components ofthe fryer 10. The controller 200 may also be coupled to the controlpanels 18, 20 to provide operating information to, and receive inputfrom the operator of the fryer 10. The controller 200 may control thetemperature of the cooking medium 40 in each fry pot 12, 14 byselectively activating the respective heating element 32, and maycontrol the filtering and addition of cooking oil by selectivelyactivating the drain valves 102, 104, filter pump 112, reservoir pump116, and motor 130 of selector valve 118.

FIG. 3 is a diagrammatic view of the controller of FIG. 2. Thecontroller 200 may include a processor 202, a memory 204, and aninput/output (I/O) interface 206. The processor 202 may include one ormore devices configured to manipulate signals and/or data based onoperational instructions that are stored in memory 204. Memory 204 mayinclude a single memory device or a plurality of memory devicesconfigured to store information in the form of data. The memory 204 maystore computer program code embodied as one or more computer softwareapplications comprising instructions executed by the processor 202, suchas a controller application 208. One or more data structures 210 mayalso reside in memory 204, and may be used by the processor 202 and/orcontroller application 208 to store and process data.

The I/O interface 206 operatively couples the processor 202 to othercomponents of the fryer 10, such as control panels 18, 20, heatingelements 32, temperature sensors 34, 128, drain valves 102, 104, filterpump 112, reservoir pump 116, and motor 130 of selector valve 118. TheI/O interface 206 may include signal processing circuits that conditionincoming and outgoing signals so that the signals are compatible withboth the processor 202 and the components to which the processor 202 iscoupled. To this end, the I/O interface 206 may includeanalog-to-digital (A/D) and/or digital-to-analog (D/A) converters,voltage level and/or frequency shifting circuits, optical isolationand/or driver circuits, data busses, and/or any other analog or digitalcircuitry suitable for coupling the processor 202 to the othercomponents of the cooking apparatus.

The control panels 18, 20 may be operatively coupled to the processor202 of controller 200 to provide a user interface that allows theoperator to interact with the controller 200. The control panels 18, 20may include a display having suitable audio and visual indicatorscapable of providing information to the operator. The control panels 18,20 may also include input devices and controls capable of acceptingcommands or input from the operator and transmitting the entered inputto the processor 202. In this way, the control panels 18, 20 may enablemanual initiation or selection of system functions, for example, duringset-up of the fryer 10.

FIGS. 4A and 4B illustrate two views of a rotary valve 400 in accordancewith one embodiment of the invention. Rotary valve 400 may include astationary hollow outer cylinder with one or more fluid inlet ports 402and one or more fluid outlet ports 404. Inlet ports 402 may beselectable or may converge to form a single inlet port. Rotary valve 400may be configured with a rotating inner cylinder (not shown in FIGS. 4Aand 4B) with channels to coincide with different outlet ports 404 as theinner cylinder rotates. As such, rotary valve 400 may be operated toselectively connect one or more inlet ports 402 with one or more outletports 404. The inner cylinder may be rotated by a motor 406 (e.g., adirect current (DC) motor). Additionally, the inner cylinder may berotated by a solenoid engaging a cam, a stepper motor, or any othermechanism to rotate the inner cylinder.

The motor 406 may be operatively coupled to the inner cylinder by atransmission 408, for example, a system of gears, chains, and/or belts.As the inner cylinder is rotated, one or more of outlet ports 404 may beselected and placed in fluid communication with one or more inlet ports402. Although prior versions of rotary valve included cams and othermechanical switches for position sensing, the rotary valve 400 of thisembodiment is advantageously configured to operate with position sensingequipment that enables continuous angular position resolution so as tobe confident the correct inlet port 402 is communicating with thecorrect outlet port 404 for a given operational state.

In this example, rotary valve 400 may further comprise a temperaturesensor 128 that resides within an internal volume 410 of the rotaryvalve 400. The temperature sensor 128 may be mounted to the stationaryhollow outer cylinder with a coupling 412. The temperature sensor 128may be coupled to the controller 200 by a conducting cable 414 thattransmits to the controller 200 a signal that is generated by thetemperature sensor 128, which may be used for various heat controlpurposes. The temperature sensor 128 measures a common temperature ofcooking media flowing through the rotary valve 400 from one or moreinlet ports 402 to the one or more outlet ports 404. It will beunderstood and also described further below that the temperature sensor128 may be duplicated and/or repositioned in different receptacles andlocations in the plumbing of the fryer, so as to provide additionalinformation to the controller 200.

FIG. 5 illustrates a set of positions of an inner cylinder within arotary valve, such as the rotary valve 400 described above, for example.An inner cylinder 502 of a rotary valve 400 may be provided in a fryercontaining four cooking vessels (not shown). Inner cylinder 502 mayrotate to at least ten discrete positions 504 as summarized in table505. Each position 504 may correspond to an outlet port 404 of rotaryvalve 400. Because each outlet port 404 may be connected to a componentof a fryer, each position 504 of inner cylinder 502 may be mapped to aspecific component 506 of a fryer. In table 505, positions 504 aremapped to specific components 506 of the fryer. For example, when innercylinder 502 is in first position 508, an outlet port 404 may be influid communication with a left vat of the first vessel of the fryer.Similarly, when inner cylinder 502 is in sixth position 516, an outletport 404 may be in fluid communication with the right vat of the thirdvessel. In some embodiments, tenth position 524 of inner cylinder 502may correspond to a receptacle of waste cooking medium and also may bethe “home” or default position of rotary valve 400. However, it will beunderstood that these particular fryer component associations with thepositions 504 in table 505 are but one example of the configurationsthat can be used when connecting the rotary valve 400 in position in thecooking medium handling system 100 of a fryer.

As initially set forth above, problems associated with mechanicalsystems for determining the rotary position of rotary valve 400 areovercome by the disclosed embodiments, as described in further detailbelow. The disclosed embodiments provide a rotary position sensor thatis configured to sense an angular position of the rotary valve withoutmaking mechanical contact with the rotary valve. In this regard, aHall-effect sensor determines a position of a magnetic field sourceresiding on the rotary valve. The disclosed position sensor isconfigured to function properly at elevated temperatures associated withthe cooking medium during operation of the cooking apparatus. Forexample, operating temperatures of the cooking medium in commercialfryers are typically in the range from 350° F. to 375° F. and may rangeas high as 400° F. Most commercially available Hall-effect sensors wouldtypically fail when trying to operate in environments with suchtemperatures. Even though one would normally be led to mechanicalsensors or other solutions for tracking the position of the rotary valve400 in view of the environment provided at a fryer, the currentembodiments achieve advantageous functionality by making the Hall-effectsensor(s) work within this environment.

FIG. 6 is a schematic illustration 600 of the operation of a Hall-effectdevice for sensing magnetic fields, according to an embodiment. TheHall-effect is based on a fundamental interaction between a magneticfield and charge carriers flowing in a flat rectangular material. Inthis example, the Hall-effect device or sensor 602 is a flat solid pieceof material (at 602) that conducts electricity with application of anapplied voltage. For example, a source 604 of direct current (DC)voltage is connected to opposite edges, 606 a and 606 b, of the material602 through wires 608 a and 608 b to apply a voltage difference betweenopposite edges, 606 a and 606 b. The applied DC voltage induces a DCcurrent 610 that flows through the material 602.

In the presence of a magnetic field source, charge carriers flowing inthe material 602 are deflected to opposite edges, 612 a and 612 b, dueto the well-known Lorentz force. The Hall-effect refers to an inducedvoltage between edges 612 a and 612 b that arises from charge thatbuilds up on opposite edges, 612 a and 612 b due to the deflection ofcharge carriers in the presence of the magnetic field. In this example,magnet 614 generates a magnetic field that gives rise to the Hallvoltage 616. In this example, magnet 614 is oriented with its north poledirected away from the material 602 and its south pole directed towardthe material 602. As such, a magnetic field pointing perpendicular tothe plane of the material 602 is generated that points toward the magnet614. In this field, positive charge carriers are deflected toward edge612 a while negative charge carriers are deflected toward edge 612 b togenerate a Hall-effect voltage with indicated polarity 618 with apositive voltage developing at edge 612 a and a negative voltagedeveloping at edge 612 b.

As described above, the Hall-effect provides a position sensor thatdetermines the presence of a magnetic field source. A linear Hall-effectsensor generates a Hall-effect voltage that depends linearly on themagnetic field strength. Thus, as magnet 614 moves closer to theHall-effect sensor 602, the Hall-effect voltage increases continuously,and as magnet 614 moves away from Hall-effect sensor 602, theHall-effect voltage decreases continuously. Thus, as described ingreater detail below, a Hall-effect sensor may be used to provide arotary position sensor that generates a signal, having continuousangular position resolution, based on an angular position of the rotaryvalve. In further embodiments, if detection of discrete angularpositions (e.g., positions 508-524 in FIG. 5) is desired, a plurality ofdigital Hall-effect sensors that provide a binary output signal, inresponse to the presence of magnetic fields having field strength aboveor below a predetermined threshold, may be employed.

FIGS. 7A and 7B illustrate the use of a Hall-effect sensor as a rotaryposition sensor that generates a signal, having continuous angularposition resolution. In this example, a magnetic field source 702 isattached to an inner cylinder 502 of a rotary valve 400 and is in closeproximity to a Hall-effect sensor 703. The magnetic field source 702 maybe a magnet 614 or a current carrying wire (or coil of wire) thatgenerates a magnetic field. In this example, magnetic field source 702is illustrated in a first angular position 704 that may be a homeposition of the inner cylinder 502 of the rotary valve. In thisconfiguration, a first value 706 of the Hall-effect voltage isgenerated, as illustrated in FIG. 7B.

Upon rotation of the inner cylinder 502, the magnetic field source 702moves to a new angular position 708. In this configuration, the distancebetween the magnetic field source 702 and the Hall-effect sensor 703 isincreased relative to that in the configuration in which the magneticfield source 702 was placed at angular position 704. The increaseddistance leads to a weaker magnetic field strength that is detected bythe Hall-effect sensor 703 which, in turn, leads to a reducedHall-effect voltage 710 as shown in FIG. 7B. Similarly, as the magneticfield source 702 is moved to positions 712, 716, 720, and 724, theHall-effect sensor provides output voltages having values 714, 718, 722,and 726, as shown in FIG. 7B. Returning the magnetic field source 702 tothe starting angular position 704 returns the Hall-effect voltage to itsinitial value 706.

Although, discrete angular positions are shown in the example of FIGS.7A and 7B, it must be emphasized that the voltage output from a linearHall-effect sensor produces a voltage output that changes continuouslywith angular position as indicated by the solid, continuous curve 728 inFIG. 7B. As shown, FIG. 7B provides ambiguous angular information in thesense that angular positions in the positive and negative sense (e.g.,712 and 720) with respect to the home position 704 produce similaroutput voltages 714 and 722 based on these angular positions beingequidistant in actual linear distance from the Hall-effect sensor 602.Thus, without further information beyond the sensor output in theabstract, only the magnitude of the angular displacement relative to thehome position 704 would be identified by sensor 703.

The controller 200, however, has additional information in that is knowsin which direction the rotary valve is being displaced. In the exampleof FIGS. 7A and 7B, a preferred direction of angular displacement (i.e.,clockwise) has been chosen. As such, the angular position may beuniquely identified as indicated by the graph in FIG. 7B. For example,if the inner cylinder 502 is being rotated in a clockwise sense, as inthe example of FIGS. 7A and 7B, the angular position may be determinedbased on whether the voltage is increasing or decreasing. For example,while rotating the inner cylinder 502 in a clockwise sense, thedecreasing voltage readings 706, 710, 714, and 718, indicate angularpositions 704, 708, 712, and 716 that fall on the left-hand side of theinner cylinder 502 in FIG. 7A, and correspond to angles having valuesbetween 0° and 180° relative to the home position 704. Similarly, whilerotating the inner cylinder 502 in a clockwise sense, the increasingvoltage readings 718, 722, 726, and 706 indicate angular positions 716,720, 724, and 704 that fall on the right-hand side of inner cylinder 502in FIG. 7A and correspond to angles having values between 180° and 360°.

The accuracy of angular position detection depends on the sensitivitywith which small changes of voltage may be detected. A simpleexperimental procedure may be employed to determine the detectionsensitivity and a calibration may be performed to associate angularposition values with a voltage vs. angle curve such as that illustratedin FIG. 7B. If greater accuracy is needed, embodiments that employ aplurality of Hall-effect sensors may be used, as described below.

To this end, another embodiment of sensors that may be used with therotary valve 400 is shown in FIGS. 8A and 8B. FIGS. 8A and 8B illustratethe use of a plurality of Hall-effect sensors to provide a rotaryposition sensor having greater accuracy, according to an embodiment.FIG. 8A shows a configuration 800 in which three Hall-effect sensors,802, 804, and 806, are used to detect an angular position of a magneticfield source 702 at various angular positions 808, 810, 812, 814, 816,and 818. FIG. 8B shows corresponding Hall-effect voltages vs. angularposition generated by the three sensors of FIG. 8A. Hall-effect sensor802 produces the voltage vs. angular position curve 820, sensor 804produces voltage vs. angular position curve 822, and sensor 806 producesvoltage vs. angular position curve 824.

FIG. 8B illustrates a situation in which similar sensors having similaroutput voltage characteristics are used for sensors 802, 804, and 806.Voltage vs. angular position curves 820, 822, and 824 are displacedcopies of one another as can be seen based on considerations of thesymmetrically placed positions of sensors 802, 804, and 806. A simpleexperimental procedure may be used to set up a calibration to associateangular position values with the three voltage vs. angle curvesillustrated in FIG. 8B. In this way, the rotational position sensor ofFIG. 8A may be used to obtain a unique identification of the angularposition of inner cylinder 502 without further information such as thespecific direction in which the inner cylinder 502 is being rotated, incontrast to the situation of the embodiment shown in FIGS. 7A and 7B.Likewise, as the output of Hall-effect sensors are sometimes affected byhigh ambient temperatures, the use of multiple sensors 802, 804, and 806can help correct for any temperature-based inaccuracies and provide theredundancy required to still achieve accurate position determinationswith continuous angular resolution.

The above-described embodiments simplify the plumbing system of cookingmedium handling system 100 through the use of a rotary valve 400 toserve multiple cooking chambers in a single system. Moreover, thedisclosed non-contact angular position sensors provide an advantageousoperation whereby the exact rotational position of the rotary valve 400is confirmed at all times, without being negatively impacted by thingslike mechanical wear of components and/or environmental conditions suchas ambient oil or water vapors and high temperatures. The plumbingsystem may further be improved by including temperature sensors andheating elements throughout the various hoses, pipes, pumps, valves,etc., of system 100 (see FIG. 2), in addition to the heating elements 32and temperature sensors 34 and 128 described above.

For example, it may be advantageous, in some cooking apparatus, to usecooking media that is solid (e.g., shortening) at room temperature.Therefore, it is necessary in such embodiments to embed heaters andtemperature sensors throughout the plumbing system so that anappropriate amount of heat may be added at startup to ensure that thecooking medium is properly melted and capable of flow throughout thesystem (the temperature sensors help monitor when such melting hasoccurred). In other operations, the temperature of cooking media may bemonitored as it flows through the system. As hot cooking media isremoved from fry pots, 12 and 14 (e.g., see FIG. 2), for example, atemperature sensor may sense a dropping temperature when the transitionfrom 300° F.+ degree oil is replaced with ˜100° F. air. This transitionmay be detected using a controller algorithm and the controller maytherefore automatically determine whether the system was pumping oil orair into fry pots 12 and 14.

Further, in a filtering operation, as cooking media is filtered, thecooking media may be significantly cooled by flowing through the drainmanifold 106 and filtration system, particularly when those elements arenot heated. As the cooking media flows back to the fry pots, 12 and 14,it would be advantageous to know the temperature of cooking media thatis being returned to the fry pots, 12 and 14, and to add heat to thereturning cooking media as needed to thereby reduce downtime before anew cooking cycle can begin. Thus, it is desirable to have a pluralityof temperature sensors and heaters throughout the plumbing system sothat the controller 200 may generate a desired temperature profilethroughout the system 100.

FIG. 9 is a flowchart illustrating a method 900 of transferring acooking medium to various parts of a cooking apparatus, such as thefryer 10 of FIG. 2. It will be understood that the following actions areactuated by the controller 200, in one embodiment. The method includesdetermining (at block 902) an angular position of the rotary valve 400,rotating (at block 904) the rotary valve to selectively position arotary inlet 402 of the rotary valve in fluid communication with one ofa plurality of rotary outlets 404 based on the detected angularposition, and transferring (at block 906) the cooking medium from acooking medium source that is in fluid communication with the rotaryinlet to a destination receptacle that is in fluid communication withone of the plurality of rotary outlets.

The stage of determining 902 an angular position of a rotary valve mayfurther include determining an angular position of the rotary valveusing a rotary position sensor that generates a signal, havingcontinuous angular position resolution, based on the angular position ofthe rotary valve. The method may further include determining the angularposition of the rotary valve by using a sensor that determines angularposition without making mechanical contact with the rotary valve. Themethod may further include determining 902 an angular position of therotary valve using a Hall-Effect sensor that functions at elevatedoperating temperatures associated with the cooking medium.

The method may further include controlling (at block 908) a temperaturewithin the plumbing system of the cooking apparatus according to apredetermined temperature profile. The method includes measuring atemperature of the cooking medium at a first plurality of locationswithin the plumbing system of the cooking apparatus, and proving heat toa second plurality of locations within the plumbing system of thecooking apparatus based on the measured temperatures at the firstplurality of locations.

In general, the routines executed to implement the embodiments of theinvention, whether implemented as part of an operating system or aspecific application, component, program, object, module or sequence ofinstructions, or a subset thereof, may be referred to herein as“computer program code,” or simply “program code.” Program codetypically includes computer-readable instructions that are resident atvarious times in various memory and storage devices in a computer andthat, when read and executed by one or more processors in a computer,cause that computer to perform the operations necessary to executeoperations and/or elements embodying the various aspects of theembodiments of the invention. Computer-readable program instructions forcarrying out operations of the embodiments of the invention may be, forexample, assembly language or either source code or object code writtenin any combination of one or more programming languages.

Various program code described herein may be identified based upon theapplication within which it is implemented in specific embodiments ofthe invention. However, it should be appreciated that any particularprogram nomenclature which follows is used merely for convenience, andthus the invention should not be limited to use solely in any specificapplication identified and/or implied by such nomenclature. Furthermore,given the generally endless number of manners in which computer programsmay be organized into routines, procedures, methods, modules, objects,and the like, as well as the various manners in which programfunctionality may be allocated among various software layers that areresident within a typical computer (e.g., operating systems, libraries,API's, applications, applets, etc.), it should be appreciated that theembodiments of the invention are not limited to the specificorganization and allocation of program functionality described herein.

The program code embodied in any of the applications/modules describedherein is capable of being individually or collectively distributed as aprogram product in a variety of different forms. In particular, theprogram code may be distributed using a computer-readable storage mediumhaving computer-readable program instructions stored thereon for causinga processor to carry out aspects of the embodiments of the invention.

Computer-readable storage media, which is inherently non-transitory, mayinclude volatile and non-volatile, and removable and non-removabletangible media implemented in any method or technology for storage ofinformation, such as computer-readable instructions, data structures,program modules, or other data. Computer-readable storage media mayfurther include RAM, ROM, erasable programmable read-only memory(EPROM), electrically erasable programmable read-only memory (EEPROM),flash memory or other solid state memory technology, portable compactdisc read-only memory (CD-ROM), or other optical storage, magneticcassettes, magnetic tape, magnetic disk storage or other magneticstorage devices, or any other medium that can be used to store thedesired information and which can be read by a computer.

A computer-readable storage medium should not be construed as transitorysignals per se (e.g., radio waves or other propagating electromagneticwaves, electromagnetic waves propagating through a transmission mediasuch as a waveguide, or electrical signals transmitted through a wire).Computer-readable program instructions may be downloaded to a computer,another type of programmable data processing apparatus, or anotherdevice from a computer-readable storage medium or to an externalcomputer or external storage device via a network.

Computer-readable program instructions stored in a computer-readablemedium may be used to direct a computer, other types of programmabledata processing apparatuses, or other devices to function in aparticular manner, such that the instructions stored in thecomputer-readable medium produce an article of manufacture includinginstructions that implement the functions, acts, and/or operationsspecified in the flow-charts, sequence diagrams, and/or block diagrams.The computer program instructions may be provided to one or moreprocessors of a general purpose computer, a special purpose computer, orother programmable data processing apparatus to produce a machine, suchthat the instructions, which execute via the one or more processors,cause a series of computations to be performed to implement thefunctions, acts, and/or operations specified in the flow-charts,sequence diagrams, and/or block diagrams.

In certain alternative embodiments, the functions, acts, and/oroperations specified in the flow-charts, sequence diagrams, and/or blockdiagrams may be re-ordered, processed serially, and/or processedconcurrently consistent with embodiments of the invention. Moreover, anyof the flow-charts, sequence diagrams, and/or block diagrams may includemore or fewer blocks than those illustrated consistent with embodimentsof the invention.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the embodimentsof the invention. As used herein, the singular forms “a,” “an,” and“the” are intended to include the plural forms as well, unless thecontext clearly indicates otherwise. It will be further understood thatthe terms “comprises” and/or “comprising,” when used in thisspecification, specify the presence of stated features, integers,actions, steps, operations, elements, and/or components, but do notpreclude the presence or addition of one or more other features,integers, actions, steps, operations, elements, components, and/orgroups thereof. Furthermore, to the extent that the terms “includes,”“having,” “has,” “with,” “comprised of,” or variants thereof are used ineither the detailed description or the claims, such terms are intendedto be inclusive in a manner similar to the term “comprising.”

While all of the invention has been illustrated by a description ofvarious embodiments, and while these embodiments have been described inconsiderable detail, it is not the intention of the Applicant torestrict or in any way limit the scope of the appended claims to suchdetail. Additional advantages and modifications will readily appear tothose skilled in the art. The invention in its broader aspects istherefore not limited to the specific details, representative apparatusand method, and illustrative examples shown and described. Accordingly,departures may be made from such details without departing from thespirit or scope of the Applicant's general inventive concept.

What is claimed is:
 1. A method of transferring a cooking medium tovarious parts of a cooking apparatus, the method comprising causing acontroller to perform the following operations: determining an angularposition of a rotary valve using a rotary position sensor that generatesa signal, having continuous angular position resolution, based on theangular position of the rotary valve; rotating the rotary valve toselectively position at least one rotary inlet of the rotary valve influid communication with one of a plurality of rotary outlets based onthe determined angular position, to thereby control flow through aplumbing system of the cooking apparatus; and transferring the cookingmedium from at least one cooking medium source that is in fluidcommunication with the at least one rotary inlet to a destinationreceptacle that is fluid communication with one of the plurality ofrotary outlets.
 2. The method of claim 1, further comprising:determining an angular position of the rotary valve using a Hall-effectsensor that determines a position of a magnetic field source residing onthe rotary valve.
 3. The method of claim 2, further comprising:determining an angular position of the rotary valve using a rotaryposition sensor that provides accurate readings of the angular positionof the rotary valve while operating in environments at temperatures upto 400° F.
 4. The method of claim 2, wherein the magnetic field sourcecomprises a magnet.
 5. The method of claim 2, wherein the magnetic fieldsource comprises a current carrying wire.
 6. The method of claim 1,further comprising: determining an angular position of the rotary valveusing a plurality of Hall-effect sensors that determine a position of amagnetic field source on the rotary valve.
 7. The method of claim 1,further comprising: determining an angular position of the rotary valvewithout making mechanical contact with the rotary valve.
 8. The methodof claim 1, further comprising: measuring a temperature of a fluid inthe form of air or the cooking medium that flows through the rotaryvalve using a temperature sensor that is mounted in an internal volumeof the rotary valve.
 9. The method of claim 1, further comprising:controlling a temperature within a plumbing system of the cookingapparatus according to a predetermined temperature profile by performingthe following operations: measuring a temperature of the cooking mediumat one or more first locations within the plumbing system of the cookingapparatus; and proving heat to one or more second locations within theplumbing system of the cooking apparatus based on the measuredtemperatures at the one or more first locations according to apredetermined temperature profile.
 10. The method of claim 1, furthercomprising performing a filtration operation using a filtration systemthat is in fluid communication with one or more cooking vessels of thecooking apparatus, the filtration operation comprising: receiving, atthe filtration system, a used cooking media from the one or more cookingvessels; causing the filtration system to filter the used cooking mediato generate filtered cooking media; and providing the filtered cookingmedia to the at least one rotary inlet as one of the at least onecooking medium source.
 11. The method of claim 10, wherein the rotaryvalve includes a plurality of inlet ports communicating with the atleast rotary inlet, the plurality of inlet ports including a first inletport, a second inlet port, and a third inlet port, and the methodfurther comprises: receiving new oil from a new oil reservoir in therotary valve via the first inlet port; receiving recycled filtered oilfrom the filtration system in the rotary valve via the second inletport; and receiving new oil from a fill port configured to supply newoil to the new oil reservoir in the rotary valve via the third inletport.
 12. A method of transferring a cooking medium to various parts ofa cooking apparatus, the method comprising causing a controller toperform the following operations: determining an angular position of arotary valve using a rotary position sensor that generates a signal,having continuous angular position resolution, based on the angularposition of the rotary valve, wherein the angular position of the rotaryvalve is determined without making mechanical contact with the rotaryvalve; rotating the rotary valve to selectively position at least onerotary inlet of the rotary valve in fluid communication with one of aplurality of rotary outlets based on the determined angular position, tothereby control flow through a plumbing system of the cooking apparatus;and transferring the cooking medium from at least one cooking mediumsource that is in fluid communication with the at least one rotary inletto a destination receptacle that is fluid communication with one of theplurality of rotary outlets.
 13. The method of claim 12, furthercomprising: determining an angular position of the rotary valve using aHall-effect sensor that determines a position of a magnetic field sourceresiding on the rotary valve.
 14. The method of claim 13, furthercomprising: determining an angular position of the rotary valve using arotary position sensor that provides accurate readings of the angularposition of the rotary valve while operating in environments attemperatures up to 400° F.
 15. The method of claim 12, furthercomprising: determining an angular position of the rotary valve using aplurality of Hall-effect sensors that determine a position of a magneticfield source on the rotary valve.
 16. A method of transferring a cookingmedium to various parts of a cooking apparatus, the method comprisingcausing a controller to perform the following operations: determining anangular position of a rotary valve using a rotary position sensor thatgenerates a signal, having continuous angular position resolution, basedon the angular position of the rotary valve; rotating the rotary valveto selectively position at least one rotary inlet of the rotary valve influid communication with one of a plurality of rotary outlets based onthe determined angular position, to thereby control flow through aplumbing system of the cooking apparatus; transferring the cookingmedium from at least one cooking medium source that is in fluidcommunication with the at least one rotary inlet to a destinationreceptacle that is fluid communication with one of the plurality ofrotary outlets; and measuring a temperature of a fluid in the form ofair or the cooking medium that flows through the rotary valve using atemperature sensor that is mounted in an internal volume of the rotaryvalve, to thereby assess and confirm a source of the fluid and whetherthe fluid is in the form of air or cooking medium.
 17. The method ofclaim 16, wherein the cooking apparatus includes a filtration system anda new oil reservoir, the filtration system configured to providerecycled and filtered oil back to one or more cooking vessels of thecooking apparatus, the new oil reservoir configured to provide new oilthat is cooler in temperature than the recycled and filtered oil, andthe method further comprises: determining whether air, new oil, orrecycled and filtered oil is being delivered through the rotary valvebased on the temperature of fluid passing through the rotary valve, asmeasured by the temperature sensor in the internal volume of the rotaryvalve.
 18. The method of claim 17, further comprising: using inputs fromthe rotary position sensor and the temperature sensor in the rotaryvalve to confirm what fluid is currently being transferred and whichsource and destination the fluid is being transferred from and to in theplumbing system based on these inputs.
 19. The method of claim 16,further comprising: determining an angular position of the rotary valveusing a plurality of Hall-effect sensors that determine a position of amagnetic field source on the rotary valve.
 20. The method of claim 16,further comprising: determining an angular position of the rotary valvewithout making mechanical contact with the rotary valve.